Domain Expansion via Network Adaptation for Solving Inverse Problems

Deep learning-based methods deliver state-of-the-art performance for solving inverse problems that arise in computational imaging. These methods can be broadly divided into two groups: (1) learn a network to map measurements to the signal estimate, which is known to be fragile; (2) learn a prior for the signal to use in an optimization-based recovery. Despite the impressive results from the latter approach, many of these methods also lack robustness to shifts in data distribution, measurements, and noise levels. Such domain shifts result in a performance gap and in some cases introduce undesired artifacts in the estimated signal. In this paper, we explore the qualitative and quantitative effects of various domain shifts and propose a flexible and parameter efficient framework that adapt pretrained networks to such shifts. We demonstrate the effectiveness of our method for a number of natural image, MRI, and CT reconstructions tasks under domain, measurement model, and noise-level shifts. Our experiments demonstrate that our method provides significantly better performance and parameter efficiency compared to existing domain adaptation techniques

Specific heat and magnetocaloric effect in Pr1-xAgxMnO3 manganites

The magnetocaloric effect in alternating magnetic fields has been investigated in Pr1-xAgxMnO3 manganites with x=0.05-0.25. The stepwise reversal of the sign of the magnetocaloric effect has been revealed in a weakly doped sample (x=0.05) at low temperatures (~80 K). This reversal is attributed to the coexistence of the ferromagnetic and canted antiferromagnetic phases with different critical temperatures.Comment: 4 pages, 4 figure

Recovery Analysis for Plug-and-Play Priors using the Restricted Eigenvalue Condition

The plug-and-play priors (PnP) and regularization by denoising (RED) methods have become widely used for solving inverse problems by leveraging pre-trained deep denoisers as image priors. While the empirical imaging performance and the theoretical convergence properties of these algorithms have been widely investigated, their recovery properties have not previously been theoretically analyzed. We address this gap by showing how to establish theoretical recovery guarantees for PnP/RED by assuming that the solution of these methods lies near the fixed-points of a deep neural network. We also present numerical results comparing the recovery performance of PnP/RED in compressive sensing against that of recent compressive sensing algorithms based on generative models. Our numerical results suggest that PnP with a pre-trained artifact removal network provides significantly better results compared to the existing state-of-the-art methods.Comment: 27 pages, 13 figure

Modeling of the natural vertically directed body waves generation processes in geological media

The report reviews interdisciplinary problem relevant to the search method hydrocarbon a low-frequency seismic sounding, based on the study of resonance properties of geological media. Problem is in the representation of the process of natural formation of a vertically directed body waves in a geological medium. In this survey was suggested and simulated a scattering mechanism of surface Rayleigh waves on inhomogeneities with Poisson's ratio different from the enclosing environment. The result of simulation of the upper part of the section as a set of layers consisting of elements with a random Poisson's ratio is observed a natural formation of a vertically directed volume waves

Характер клинических проявлений ожогов глаз у пациентов с различным фенотипом ацетилирования при нормализованном внутриглазном давлении

PURPOSE: To study the character of clinical manifestations of ocular burns in patients with normal IOP and different acetylation phenotypes (APh).METHODS: We examined 103 patients with ocular burns (141 eyes) during their primary visit to the Republican Clinical Eye Hospital of the Ministry of Health of Uzbekistan, on different time-points during therapy (on days 2, 5, 7, 12 after the beginning of treatment) and then during an active clinical examination 30 days and 4 months after discharge. 44 patients were examined 1-2 years after suffering a burn injury in order to identify the later post-burn complications and their interpretation according to the patient’s APh. 52 (69 eyes) patients out of 103 examined patients (141 affected eyes) had a slow acetylation phenotype (SA) and 51 patients (72 eyes) — a fast acetylation phenotype (FA).RESULTS: The results of these studies allow us to assert that patients with SA phenotype develop deeper ocular burns, with eye tissue damages less prone to treatment than in FA patients, where less pronounced changes lead to faster process normalization. APh determines the course of the manifestations, their severity and risk of complications in ocular burns patients. Fast acetylation phenotype may serve as a prognostic marker of faster pathological changes regression in ocular tissues, whereas the slow acetylation phenotype suggests the development of more severe disease forms, often requiring a prolonged and complex therapy. ЦЕЛЬ. Изучить характер клинического течения поражения глаза при химических ожогах в зависимости от фенотипа ацетилирования (ФА) при нормализованном внутриглазном давлении (ВГД).МЕТОДЫ. Были обследованы 103 больных с ожогами глаз (141 глаз): при первичном обращении, на этапах терапии (2, 5, 7, 12 сутки от момента обращения в клинику) и при активной диспансеризации в сроки 30 дней и 4 мес. после выписки. Через 1-2 года после перенесенной ожоговой травмы с целью выявления поздних послеожоговых осложнений и их интерпретации с учетом ФА также были обследованы 44 пациента. Из общего числа 103 обследованных лиц (141 пораженный глаз) — 52 (69 глаз) больных были с медленным типом фенотипа ацетилирования (МА) и 51 больной (72 глаза) — с быстрым типом ацетилирования (БА).РЕЗУЛЬТАТЫ. Результаты проведенных исследований позволяют утверждать, что при ожогах глаз при МА развиваются более глубокие, тяжело поддающиеся лечению деструктивные нарушения в тканях глаза, при БА — менее выраженные изменения, которые в дальнейшем быстрее приводят к нормализации процесса. ФА определяет характер течения, тяжесть и риск развития осложнений при ожогах глаз. БА может служить прогностическим маркером к более быстрой регрессии патологических изменений в тканях глаза, МА предполагает к развитию более тяжелых форм с затяжным и осложненным течением, трудно поддающихся традиционной терапии.

Effect of structural defects on anomalous ultrasound propagation in solids during second-order phase transitions

The effect of structural defects on the critical ultrasound attenuation and ultrasound velocity dispersion in Ising-like three-dimensional systems is studied. A field-theoretical description of the dynamic effects of acoustic-wave propagation in solids during phase transitions is performed with allowance for both fluctuation and relaxation attenuation mechanisms. The temperature and frequency dependences of the scaling functions of the attenuation coefficient and the ultrasound velocity dispersion are calculated in a two-loop approximation for pure and structurally disordered systems, and their asymptotic behavior in hydrodynamic and critical regions is separated. As compared to a pure system, the presence of structural defects in it is shown to cause a stronger increase in the sound attenuation coefficient and the sound velocity dispersion even in the hydrodynamic region as the critical temperature is reached. As compared to pure analogs, structurally disordered systems should exhibit stronger temperature and frequency dependences of the acoustic characteristics in the critical region.Comment: 7 RevTeX pages, 4 figure

Нейробиохимические критерии диагностики глазного ишемического синдрома

PURPOSE: To investigate abnormalities of neurospecific protein S-100 level in patients with ocular ischemic syndrome. METHODS: The material included 28 people aged 59 to 79 years. Control group consisted of 10 volunteers without ophthalmic symptoms, main group (Group 2) consisted of 18 patients with ocular ischemic syndrome. Neurospecific protein level was determined by means of chemiluminescence immunoassay in blood serum and lacrimal fluid by an automatic electrochemiluminescence immunoassay analyzer Cobas e 411 («Roche Diagnostics», Switzerland). The amount of protein in the fluid up to 0.105 mmol/l was considered a normal value. RESULTS: The study established that the levels of S-100 in the control group were 0.0914±0.0012 mmol/l in lacrimal fluid and 0.0712±0.0021 mmol/l in blood serum, which was within normal range. In the main group lacrimal levels of S-100 protein were increased in 18 patients and averaged 5.871±0.027 mmol/l (pЦЕЛЬ. Изучение нарушения уровня нейроспецифического белка S-100 при глазном ишемическом синдроме (ГИС). МЕТОДЫ. Материалом послужили данные 28 человек в возрасте от 59 до 79 лет. Контрольную группу составили 10 добровольцев без офтальмологической симптоматики, основная группа (2 группа) состояла из 18 пациентов с ГИС. Количество нейроспецифического белка определялось с помощью хемилюминесцентного иммуноанализа в сыворотке крови (СК) и слезной жидкости (СЖ) на автоматическом электрохемилюминесцентном иммуноанализаторе Cobas e 411 («Roche Diagnostics», Швейцария). Нормальными показателями считали количество белка в жидкости до 0,105 ммоль/л. РЕЗУЛЬТАТЫ. По результатам исследования было выявлено, что у больных контрольной группы показатели белка S-100 в СЖ составили 0,0914±0,0012 ммоль/л, в СК - 0,0712±0,0021 ммоль/л, что было в пределах нормы. У больных основной группы показатели данного белка в СЖ были повышены у всех больных и составили в среднем 5,871±0,027 ммоль/л (

Quantization and Compressive Sensing

Quantization is an essential step in digitizing signals, and, therefore, an indispensable component of any modern acquisition system. This book chapter explores the interaction of quantization and compressive sensing and examines practical quantization strategies for compressive acquisition systems. Specifically, we first provide a brief overview of quantization and examine fundamental performance bounds applicable to any quantization approach. Next, we consider several forms of scalar quantizers, namely uniform, non-uniform, and 1-bit. We provide performance bounds and fundamental analysis, as well as practical quantizer designs and reconstruction algorithms that account for quantization. Furthermore, we provide an overview of Sigma-Delta ($\Sigma\Delta$) quantization in the compressed sensing context, and also discuss implementation issues, recovery algorithms and performance bounds. As we demonstrate, proper accounting for quantization and careful quantizer design has significant impact in the performance of a compressive acquisition system.Comment: 35 pages, 20 figures, to appear in Springer book "Compressed Sensing and Its Applications", 201